The U.S. is in a “weaker position all around the world” today than it was four years ago, he said. “I can’t think of a single place in the world where we’re better off today than we were four years ago.”

It’s not about having more or less military power, Portman said, it’s about being consistent in supporting American principles.

“When you say something as America, you need to stand behind it. When you draw a red line, you need to stand behind it,” he said.